Device for manufacturing a lamp

ABSTRACT

Apparatus for manufacturing miniature signal lamps each having a base filament supports projecting radially from the center of the base. Originally these supports lie in a common plane. The free end portion of each filament support is connected to a filament. The apparatus comprises means for forming a portion of each filament support into a V-shaped configuration lying in a plane substantially perpendicular to the common plane, wherein alternate ones of said V-shaped portions point in one direction longitudinal of the lamp and the remaining ones point in the opposite longitudinal direction. The apparatus also has means for pressing the V-shaped portions into acute-angled forms, to thereby make it possible to manufacture extremely small lamps.

United States Patent [1 1 Rochet I [4 1 Sept. 30, 1975 Related U.S. Application Data [62] Division of Ser. No. 336,248, Feb. 27, 1973, Pat. No.

Jean Rochet, Asnieres, France [30] Foreign Application Priority Data Feb. 29, 1972 France 72.06850 [52] US. Cl 140/71.5; 29/25.18 [51] Int. Cl. B21F 45/00 [58] Field of Search 29/25.18; 140/71.5, 71.6, 140/105; 267/159 [56] References Cited UNITED STATES PATENTS 1,881,981 10/1932 Trussell 140/105 2,683,473 7/1954 Flaws et a1... l40/7l.6

2,736,344 2/1956 Dilts 140/71.6 3,058,497 10/1962 Buck l40/71.6 3,172,432 3/1965 Hawkcy et al.. l40/71.6 3,364,379 l/l968 Munday et a1 l40/7l.6

3,748,888 7/1973 Gerich 72/375 FOREIGN PATENTS OR APPLICATIONS 16,530 1907 United Kingdom 140/7l.6

Primary ExaminerC. W. Lanham Assistant Examiner-E. M. Combs Attorney, Agent, or FirmRobert E. Burns; Emmanuel J. Lobato; Bruce L. Adams [5 7 ABSTRACT Apparatus for manufacturing miniature signal lamps each having a base filament supports projecting radially from the center of the base. Originally these supports lie in a common plane. The free end portion of each filament support is connected to a filament. The

' apparatus comprises means for forming a portion of each filament support into a V-shaped configuration lying in a plane substantially perpendicular to the common plane, wherein alternate ones of said V- shaped portions point in one direction longitudinal of the lamp and the remaining ones point in the opposite longitudinal direction. The apparatus also has means for pressing the V-shaped portions into acute-angled forms, to thereby make it possible to manufacture extremely small lamps.

7 Claims, 10 Drawing Figures Sept. 30,1975 Sheet 1 of 3 3,908,714

US. Patent US. Patent Sept. 30,1975 Sheet 2 of3 3,908,7'14

US. Patent Sept. 30,1975 Sheet 3 of3 3,908,.714

DEVICE FOR MANUFACTURING A LAMP This is a division, of application Ser. No. 336,248, filed Feb. 27, 1973, now US. Pat. No. 3,837,37l.

BACKGROUND OF THE INVENTION This invention relates to devices for manufacturing miniature signal lamps.

Already known are miniature lamps of very small diameter less than 14 mm, these lamps functioning under standard voltages of 48, 60, 130 V and above. Some of these lamps are at present manufactured manually, starting with the base, by manual fitting of a filament holder formed by a number of hook-supports, made of molybdenum, in principle with an odd number of these, from three to eleven hooks arranged radially. After the free ends of each filamentary support have been wound round the conducting filament of the lamp, the supports are folded back manually in a non-uniform manner, in such a way that on the one hand a quasi-perfect conductor voltage is obtained and on the other hand the maximum final overall diameter of the lamp is reduced to a minimum; in spite of this operation, the diameter remains around 14 mm.

Also, former devices for the indicated purposes were complicated. costly, and unreliable. In particular they were imperfect with respect to the forming of the filament support wires of the lamp, and the resulting lamp diameter.

OBJECT AND NATURE OF THE INVENTION The purpose of this invention is to eliminate thisdisadvantage, and it therefore provides a new miniature lamp of this type particularly suitable for automatic mass production in large runs, and which above all has the advantage of having a final mounting diameter considerably smaller than the diameter of lamps known today since it is reduced to a value of around 8 mm.

To achieve this, this miniature signal lamp with base. having a filament connected to power supply wires lodged in the base and secured by a number of radial filamentary supports, each of the latter havinga first end fixed into a central bead of the base, and its other free end folded over on itself, to form a loop through which the filament passes, is characterised in that'th'e various filamentary supports are folded into V-shapes open alternately towards the top and towards the bottom around the base of the lamp.

The miniature lamp in conformity with the invention thus offers the advantage that due' to the mechanical folding into V-folds of the filamentary supports, its overall diameter is considerably reduced and can be reduced as required to a maximum 8 mm for the finished lamp. Furthermore, due to the alternating opening towards the top and towards the bottom'of the successive folds formed by the filamentary supports, the filament follows a zig-zag path and is thus perfectly tensioned. Finally the lamp in conformity with the invention is particularly suitable for automated production.

The invention provides a device for manufacturing basemounted miniature signal lamps with central bases fitted with radial filament supports. Theends of the filament supports are formed into loops'in'which a filament is held in position. Each filament support is folded into a \/-shape, at a point roughly in its middle. This is done alternately towards the top and towards the bottom, for the various filament supports arranged in 'a star shape around a central bead. A die unit thcn'compresses the Vshapes to confine them to a region close to the base. The die unit comprises a cylindrical, hollow body with radial fingers slideable'therein to operate on the filament support wires of a lamp base.

BRIEF DESCRIPTION OFTHE DRAWINGS:

An embodiment of this invention is described below, by way of example only, with reference to the annexed drawings, of which:

FIG. 1 shows a schematic vertical projection of a miniature lamp base as it appears before the first stage in the process of manufacturing the lamp, i.e. with head downwards.

'FlGi 2 shows the lamp base of FIG. 1 along line "in FIG'. I.

FIG'. 3 shows an identical schematic vertical projection of the base after winding of the freeends of the filamentary supports around the filament.

FIG. 4 shows an identical schematic vertical projection of the base after shaping of the V-folds in the centres of the filamentary supports.

FIG. 5 shows an identical schematic vertical projection of the ba se after a further shaping operation on the supports which brings the V-folds' closer to the axis FIG. 6 shows a view'from above of the punch which produces the V-folds on the supports alternately towards the top and towards the bottom. FIG; 7 shows 'a vertical projection of the punch shown in FIG. 6.

FIG. 8' shows a vertical projection of the bottom matrix corresponding to the pun'chshown in FIG. FIGS. 9 and I0 showrespectively a vertical projection and a view from above ofthe device by means of which the V-folds of thc' filamentary supports are brought closer to the axis of the lamp base.

DESCRIPTION OF THE PREFERRED EMBODIMENT Base 1 of the miniature signal lamp is shown in FIG. I as it appears in the 'rhan'ufacturing operationflthat' is. with its top'andbottom' parts inverted; howeverfithesc top and bot'tomparts WIII be described as such. The

base comprises a cylindrical body 2 ending at the top -in a nipped sectionorsphere' 3, and ending at its botbase 1 are embedded twd' electrodes or conductors 6 and 7, for the power supply to filament 8 connected at their top ends which project ab'ove nipped section 3. Filament 8 is shown not'yet mounted in FIG. I.

At one of its ends, the bas'eand stem- 1 has a central glass bead 9 into which are fixed the'ends of the radial filamentary'supports 10, only two of which are shown in FIG. 1. Thesesupports generally are of molybdenum. They are of a number varyinghetween 3 and II for example, and are generally ofan'odd number. For the v'iewsfrom above of the lamp and its manufacturing devices, FIGS. 2, 6 and 10, the number selected for'the supports is the traditional-number of 7 arranged in a star pattern around the central bead 9. The overall diameter a between the external ends of the two opposite filamentary supports- 1 0 is around 20 mm before any if' riaii'ipulation ofsaid supports.

free end's lda of filament supports lllare formed intoiloops or 'pigs tails 11, around filament 8. The

of t heilam'p appears after the formation of these loops, as it is shown in FIGS. 3, i.e. with its filament 8 held in position by loops 11. We then obtain a base as shown in Fl(]. 4 in which can be seen on the lefthand side a V-fold 12 with its point towards the bottom. formed from left-hand support 10, and another \/'-fold 13 with its point towards the top, formed from the opposite filamentary support. For this purpose the machine uses a bottom matrix 14 (HQ. 8) and a corresponding top punch 15 (FlGS. 6 and 7). Matrix 14 has a central axis recess 16 into which bead 9 is inserted and in an end surface 17 of the said matrix there are radial grooves into which are seated the various filamentary supports the ends of which have been previously looped. This matrix 14 is operated with a top punch with axial movement 18, the punch having on its bottom end face 19 ribs complementary to the grooves in the matrix; the ribs are distributed around the axis of the punch and offer successive peaks 20 and hollows 21 engaging respectively with complementary hollows 22a and peaks 22, of the same shape, provided in the grooves to form, from the filamentary supports 10 seated in these grooves, V-folds opening alternately towards the top and towards the bottom. Advantageously each peak 20 of the punch and 22 of the matrix has a recess 23 for loop 11 of support 10. The punch 15 furthermore has an axial recess 24 over its entire height to permit penetration by the lamp base.

Folding into V-folds alternately towards the top and towards the bottom of supports 10, obtained either by downwards movement 18 of the punch, or by the upwards movement 25 of the matrix, or by a combination of these two movements. has the effect:

- of tensioning the filament, and

- of reducing the mounting diameter of the lamp as can be clearly seen in FIG. 4.

A second deformation ofthc filamentary supports 10 is carried out by exerting on folds l2 and 13 thrusts directed towards the axis of lamp base stem 1, in the direction shown by arrows fl and f2 in FIG. 5. Asa result, the \/-fold 12 is shifted further towards the bottom and towards the axis of the base whilst conversely the opposite fold 13 is pushed further towards the top and towards the axis. The tension of filament 8 is further improved by this operation.

Folding into a V-shape of the filamentary support and its supplementary deformation permit a considerable reduction in the diameter of the lamp once mounted, a diameter which attains a maximum of 8 mm. All the folding operations of the filamentary supports 10 can be carried out very easily on known types of automatic mounting machines.

The second or supplementary shaping operation on supports 10 can be carried out by means of the device shown in FIGS. 9 and 10 by way of example. This device consists of an essentially cylindrical body 26 comprising a central chamber 27. Stem l is shown schematically at the top section of body 26 with its filaments 10 already folded at their centres. On upwards movement ofa cylindrical control cam 28 with a tapered head. pistons 29, mounted to slide in body 26, retreat and cause a rotational movement of levers 30 around their re spective axes 31, with engagement with two parallel wings 32a and 32/) of a jaw 32. Each lever 30 oscillates on a vertical plane and produces at its top end a movement of adjusting pushbutton 33 facing the axis of body 26. The pushbutton 33, screwed onto the top part of lever 30 and adjustable in position by means of'its hexagonal head 33a and its lock nut 34, is in Contact with the rear surface of a radial finger 35, which presses the ends of supports 10 towards the axis of the lamp base. Advantageously the front surface 36 of finger 35 in contact with support 10 comprises a vertical groove ensuring perfect holding of the said filament and holding it in position during its return movement.

After supplementary deformation of each filamentary support the cam 28 is lowered again and each finger 35 is retracted by means of a spring-blade 37, and by its final movement the finger makes lever 30 pivot in the opposite direction, which has the effect of returning piston 29, disengaged from the inclined surface 28a of the cam, towards the centre of body 26. The fingers 35 can be mounted so as to slide in body 26, or in another version can be mounted between the top surface 260 of the body and a circular flange 39 screwed at 38 on the latter.

As a simplification of the latter device, we have ar ranged on an identical vertical plane a piston 29, a lever 30, an adjustable pushbutton 33 and a finger 35, each of these units operating on a single support 10, but all other versions apart from the star-arrangement of the 7 distinct units form an integral part of the framework of this invention. The same applies to all conceivable variations in the number of supports 10, the shape and position of each V-fold, and the device (matrix and punch) permitting the folding of the latter.

As shown in FIGS. Sand 9 matrix 14 has a cylindrical matrix holder 14a, extending in a direction normal to the end face of the matrix, and cam 28 has a cylindrical axial recess 28a. The recess 280 can be dimensioned to fit the matrix holder 1411. Thus the device enables inscrtion of the matrix in chamber 27, coaxially with the stem 1, for performance of the first shaping or folding operation, and subsequent removal of the matrix for the second shaping operation. This arrangement facilitates registering of the folds it), initially shaped by the matrix and punch means, with the secondary shaping fingers 35.

I claim:

1. Apparatus for manufacturing a lamp of the type receptive of a lamp base having a longitudinal axis and radially projecting filament supports projecting therefrom and lying in substantially a common plane and connected to a filament at one end portion thereof farthest from said longitudinal, said apparatus comprising means for forming a portion of each filament support including said one end portion thereof into a V-shaped configuration lying in a plane substantially perpendicular to said common plane including means for forming alternate ones of said \/-shaped portions to point in one longitudinal direction and the remaining ones to point in the opposite longitudinal direction.

2. In an apparatus according to claim 1, additional means for reducing the radially projection of the support members including means for bending each support member towards said longitudinal axis thereby decreasing the angle of the vertex of the V-shaped portion thereof.

3. Apparatus for manufacturing a lamp, comprising;

holder means receptive of a lamp base which has a longitudinal axis and filament support wires radially projecting therefrom for connection to a filament at one end portion of each filament support wire farthest from said longitudinal axis;

. ,a pair of die means movable relative to one another and to the holder means along said axis for initially forming a portion of each filament support wire, including said one end portion thereof, into a V- shaped configuration lying in a plane radial of said axis; and

means for finally forming the initially formed portion of each filament support wire into a narrower V- shaped configuration, comprising a plurality of elongate members positioned on said holder means, each member extending radially of said axis, and means for moving said members radially inwardly each into contact with said one end portion of a filament support wire, and further inwardly toward said axis.

4. Apparatus according to claim 3 wherein each of said members comprises a finger, the fingers being supported by peripherally distributed portions of said body.

5. Apparatus according to claim 4 wherein each finfor effecting controlled simultaneous movements of said fingers, comprising a plurality of pushbuttons disposed radially of said body, one for each finger; a plurality of lever means, each supporting one of the push buttons aligned with one of the fingers; means for rock- 'ing the levers to move the pushbuttons and thereby the fingers toward said axis; and means for biasing the fingers away from said axis.

7. Apparatus according to claim 3 in which said die means are disposed to enable the initial forming of the wires into V-shaped wire folds alternately in opposite axial directions. 7 

1. Apparatus for manufacturing a lamp of the type receptive of a lamp base having a longitudinal axis and radially projecting filament supports projecting therefrom and lying in substantially a common plane and connected to a filament at one end portion thereof farthest from said longitudinal, said apparatus comprising means for forming a portion of each filament support including said one end portion thereof into a V-shaped configuration lying in a plane substantially perpendicular to said common plane including means for forming alternate ones of said V-shaped portions to point in one longitudinal direction and the remaining ones to point in the opposite longitudinal direction.
 2. In an apparatus according to claim 1, additional means for reducing the radially projection of the support members including means for bending each support member towards said longitudinal axis thereby decreasing the angle of the vertex of the V-shaped portion thereof.
 3. Apparatus for manufacturing a lamp, comprising; holder means receptive of a lamp base which has a longitudinal axis and filament support wires radially projecting therefrom for connection to a filament at one end portion of each filament support wire farthest from said longitudinal axis; a pair of die means movable relative to one another and to the holder means along said axis for initially forming a portion of each filament support wire, including said one end portion thereof, into a V-shaped configuration lying in a plane radial of said axis; and means for finally forming the initially formed portion of each filament support wire into a narrower V-shaped configuration, comprising a plurality of elongate members positioned on said holder means, each member extending radially of said axis, and means for moving said members radially inwardly each into contact with said one end portion of a filament support wire, and further inwardly toward said axis.
 4. Apparatus according to claim 3 wherein each of said members comprises a finger, the fingers being supported by peripherally distributed portions of said body.
 5. Apparatus according to claim 4 wherein each finger has an end surface facing inwardly of said body, with a groove in said surface parallel to said axis and disposed to receive said outer end portion of a respective, initiAlly formed filament support wire.
 6. Apparatus according to claim 4 including means for effecting controlled simultaneous movements of said fingers, comprising a plurality of pushbuttons disposed radially of said body, one for each finger; a plurality of lever means, each supporting one of the pushbuttons aligned with one of the fingers; means for rocking the levers to move the pushbuttons and thereby the fingers toward said axis; and means for biasing the fingers away from said axis.
 7. Apparatus according to claim 3 in which said die means are disposed to enable the initial forming of the wires into V-shaped wire folds alternately in opposite axial directions. 